There are numerous applications in automotive and aircraft structures, for example, where electrical wiring or other heat sensitive components pass near or through regions of relatively high temperature. Conversely, there are sometimes applications where tubing carrying a relatively high temperature fluid passes near components that may be subject to degradation at elevated temperature. In any of these applications, it may be desirable to provide heat shielding between high temperature regions and components, such as insulation on wiring, that may be subject to degradation.
This can be a significant issue for a wiring cable harness, for example, where a bundle of wires passes near a heat source such as an auto or truck exhaust header, turbocharger or the like. It may be necessary to apply heat shielding around the cable harness in only a relatively short portion of its total length. It is desirable to apply such a heat shielding after the harness is assembled so that connectors and the like do not need to be pulled through a heat-shielding tube. There are also situations where it is desirable to apply heat shielding in a retrofit application where wiring or tubing is already in place and heat shielding is to be added.
Heat shielding has previously been applied in tubular form in such situations by stitching tongue and groove or other closeable fasteners along the length of each edge of a sheet of heat-shielding material. For example, Velcro (TM) hook and loop fastener material may be stitched along opposite edges of a sheet. Such a sheet may then be wrapped around a cable harness or the like, and the edge connectors inter-engaged to form a tube of heat-shielding material around the wiring harness. Staples have also been used for connecting the edges of heat shielding. Wire or fiber ties may also be wrapped around the heat shielding to form a tube.
There can be drawbacks to such an arrangement due to the cost of the edge attachments and their stitching to the heat-shielding material. Furthermore, the stitching requires penetration of the heat-shielding material, leaving holes through which gases may flow and a potential line of weakness along which the heat-shielding material may fail. Any suitable heat-shielding material must have sufficiently robust high temperature properties to withstand the operating conditions in the automotive or other high temperature environment. For automotive applications in particular, cost is also an important consideration.
There is, therefore, provided in practice of this invention, according to a presently preferred embodiment, a closeable heat-shielding jacket which is formed from a substantially impervious flexible sheet of polymer-coated woven glass fiber textile. The textile has a substantially continuous layer of reflective metal on one face. A strip of acrylic pressure-sensitive adhesive is adhered along one edge of the aluminum layer for use in closing the heat-shielding jacket. The adhesive is selected to be resistant to continuous exposure to at least 150xc2x0 C. The heat-shielding jacket material has a removable release layer over the strip of pressure-sensitive adhesive.